Well, first off, while i believe this hilt is a contemporary, non-traditional form, i personally find it very appealing.
I don't think it is ivory (certainly not elephant or whale) and it doesn't look anything like the moose antler that many modern Bali carvings are done with. It could be some other type of antler or dense bone.
What does it feel like? is it heavy or light? Does it feel cool to the touch?